Improvement in valve-gearings



J. S'ANGSTER '8L V. H..BECKER.

Improvement in Valve-Gearing.

Patented Nov. 19, 1872.

Fig. 1

dla/MAM f/@MJZZ inventory.

UNITED STATEs PATENT EErcE.

JAMES SANGSTER AND VICTOR H. BECKER, OF BUFFALO, NEW YORK.

IMPROVEMENT IN VALVE-GEARLNGS.

Speciiication forming part of Letters Patent No. 133,121, dated November19, 1872.

To all whom it may concer-n:

Be it known that we, J AMEs SANGsTEE and VICTOR HgBEcKEE, both of Bualo,in the county of Erie and State of New York, have invented certain newand useful Improvements in the Construction of Steam-Engines, of whichthe following is a specification:

Our improvements relate to that class of engines termed reversible, andmore particularly to the construction of the valve-gear of such engines.The invention consists in providing the eccentric-rod of asingle-eccentric reversible steam-engine with a device for increasing ordecreasing the distance between the center of movement of the valve andthe shaft also, in arranging the valve and' steamports in such a mannerthat a lengthening or shortening of the eccentric-rod will change therelation they bear to each other sufciently to reverse the engine.

In the accompanying drawing, Figure I is a sectional elevation of thatportion of a steamengine embodying our improvements, wherein theeccentric-rod is shown in position for running the engine forward. Fig.II is a like view, showing the eccentric-rod in position for runningbackward.

Like letters of reference designate like parts in each of the figures.

A is the cylinder of a steam-en gine, of which B is the steam-chest anda is the exhauststeam-port 5 this and the steam-ports b and b are ofordinary construction. c c are auxiliary passages or depressions formedin the valve-face of the cylinderone on either side of the ordinarysteam-ports. C is the valve, which can be constructed in the form toreceive either a sliding or a rocking motion. l d' are the passages ordepressions cast in the face of the valve. D is the valve-arm, and E theeccentric-rod, which is connected by a joint, e, to an arrangement oflevers, F, for raising and lowering it. G is the crank-shaft,

vand g the eccentric set thereon; this eccentric is set in such aposition on the shaft in relation to the crank as will operate the valveto run the engine backward when the joint in the eccentric-rod is in theposition shown in Fig. II, it being set with the lead for running thatway. The engine is reversed by raising the joint to the position shownin Fig. I, which gives the lead to the valve for running forward.

The operation of our invention is as fol-l lows: The joint e in theconnecting-rod being in the position shown in Fig. II, and the pistonbeing in the center of its movement, the steam-port communicating withthe front end of the cylinder is full open, steam being admitted throughthe auxiliary passage c into the depression d cast in the face of thevalve, from whence it passes through the steam-port b into the front endof the cylinder, the steam contained in that portion of the cylinderbackward of the piston is being exhausted precisely as an ordinary valvewould exhaust itviz., through the communication formed with the exhaustport by the depression d in the valve. The piston now having arrived atthe forward end of its stroke, the valve has had acorrespondingly-forward movement, and has closed the exhaust-port onthat side and opened the lead through the auxiliary passage c into thedepression d of the valve, and through the port b against the backwardside ofthe piston, forcing it forward to the other end of the cylinder,when the lead is opened to return it, repeating the operation. The jointe, being raised into the position shown in Fig.

I, pushes the valve forward until a full port of steam communicates withthe backward side of the piston, forcing it to the front end of the`cylinder, and, by the motion which it communicates to the shaft, movingthe valve so as to give it the required lead-opening at that end. Thesteam, in this case, is admitted to the opposite end of the cylinder, bythe alternate opening of the main port b and auxiliary passage c.

In running the engine forward, the auxiliary lpassa-ge c is outside ofthe movement of the valve, and not used; whereas,1n the oppo' sitemovement of the engine, both the passages c and c are used in admittingsteam to the opposite ends of the cylinder.

In opening the steam-ports for the backward revolutions of the engine,the valve moves in a direction opposite that of the piston; after thecrank has passed the center, while, in the forward movement, it moves inthe same direction Withiz.Y

Claims.

1. In a sin glo-eccentric reversible steam-engine, the combination, withthe eccentric and valve, of the jointed eccentric-rodE and lever F, whenconstructed and operated substantially as described.

2. A valve having depressions d and d Witnesses:

AMos W. SANGSTER, CLAUDE PETIT.

